Exemption

81. Facilities that repackage
chlorine, provided all the following conditions are satisfied:

(a) The repackaging shall be in United States Department of
Transportation approved chlorine cylinders not exceeding one ton in
capacity.

(b) There shall be no more than two tons of chlorine on the
property at any time.

(c) All handling of chlorine shall be in accordance with
applicable Chlorine Institute Guidelines.

(d) The facilities shall be located no closer than 300 feet
from any recreational area or residence or other structure not
occupied or used solely by the owner or operator of the facilities
or the owner of the property upon which the facilities are located.

(e) The repackaging system shall be operated under vacuum at
all times and all venting of lines and cylinders shall be routed to
a caustic scrubbing system that prevents release of chlorine to the
atmosphere during all operating and maintenance activities. When
the scrubbing system is not operating properly, no chlorine shall
be repackaged.

(f) Chlorine gas shall not be vented directly to the
atmosphere under any circumstances.

82. Any vessel storing carbon
compounds composed only of carbon, hydrogen, or oxygen, provided
that the vessel vent is directed to an incinerator, boiler, or
other firebox having a stationary flue or a waste gas flare system
that will operate with no visible emissions except as provided by
30 TAC Chapter 101 for periods of maintenance or operational upset.
However, vessels not exceeding 100 barrels capacity and storing
only liquid petroleum gas may have the safety relief valve vent
directly to the atmosphere. Also, any tank having a capacity not to
exceed 1,000 gallons and storing only commercial odorants used to
odorize petroleum gases may have the safety relief valve vent
directly to the atmosphere.

83. Any tank or other container
storing carbon compounds, provided that the tank or container
pressure is sufficient at all times to prevent vapor or gas loss to
the atmosphere or the tank or container is equipped with a relief
valve which directs all vapors or gases to an incinerator, boiler,
or other firebox having a stationary flue or a waste gas smokeless
flare system. The vapors or gases and any necessary fuel gas shall
be mixed thoroughly upstream of the heater burner(s) or the flare
tip such that the mixed gases have a minimum net or lower heating
value of 200 British thermal units per cubic foot. The flare also
shall meet the other requirements of Standard Exemption 80.

84. Anhydrous ammonia storage tanks
and distribution facilities that meet the following conditions:

(a) All valves, connectors, and hoses shall be properly
maintained in leak-proof condition at all times.

(b) The capacity of the storage tanks is 30,000 gallons or
less.

(c) When transferring ammonia, all vapors shall be vented back
to the host tank and never to the atmosphere.

(d) When relieving pressure from connectors and hoses, all
vapors shall be bled into an adequate volume of water and never to
the atmosphere.

(e) Each tank is equipped to prevent unauthorized operation.

(f) Before construction begins, written site approval must be
received from the Regional Director and the owner or operator shall
file with the Texas Natural Resource Conservation Commission Office
of Air Quality in Austin a completed Form PI-7 and supporting
documentation demonstrating that all of the requirements of the
exemption will be met.

(g) The tank is located at least 1/4 mile from any
recreational area or residence or other structure not occupied or
used solely by the owner of the property upon which the facility is
located.

86. Any fixed or floating roof
storage tank, or change of service in any tank, used to store
chemicals or mixtures of chemicals shown in the enclosed Table 86A provided that the following conditions
are met:

(a) The tank is located at least 500 feet away from any
recreational area or residence or other structure not occupied or
used solely by the owner of the facility or the owner of the
property upon which the facility is located.

(b) The true vapor pressure of the compound to be stored is
less than 11.0 psia at the maximum storage temperature.

(c) For those compounds that have a true vapor pressure
greater than 0.5 psia and less than 11.0 psia at the maximum
storage temperature, any storage vessel larger than 40,000 gallons
capacity shall be equipped with an internal floating cover or
equivalent control.

(1) An open top tank containing an external floating roof
using double seal technology shall be an approved control
alternative equivalent to an internal floating cover tank, provided
the primary seal consists of either a mechanical shoe seal or a
liquid-mounted seal. Double seals having a vapor-mounted primary
seal are an approved alternative for existing open top floating
roof tanks undergoing a change of service.

(2) The floating cover or floating roof design shall
incorporate sufficient flotation to conform to the requirements of
American Petroleum Institute Code 650, Appendix C or an equivalent
degree of flotation.

(d) Compounds with a true vapor pressure of 0.5 psia or less
at the maximum storage temperature may be stored in a fixed roof or
cone roof tank which includes a submerged fill pipe or utilizes
bottom loading.

(e) For fixed or cone roof tanks having no internal floating
cover, all uninsulated tank exterior surfaces exposed to the sun
shall be painted chalk white except where a dark color is necessary
to help the tank absorb or retain heat in order to maintain the
material in the tank in a liquid state.

(f) Emissions shall be calculated by methods specified in
Section 4.3 of the current edition of the United States
Environmental Protection Agency Publication AP-42. This document
may be obtained from the Superintendent of Documents, Washington
D.C. 20402. It is Stock Number 0550000251-7, Volume I.

(g) Before construction begins, storage tanks of 25,000
gallons or greater capacity and located in a designated
nonattainment area for ozone shall be registered with the Texas
Natural Resource Conservation Commission Office of Air Quality in
Austin using Form PI-7. The registration shall include a list of
all tanks, calculated emissions for each carbon compound in tons
per year for each tank, and a Table 7 of Form PI-2 for each
different tank design.

(h) Mixtures of the chemicals listed in Table 86A which contain more than a total of 1.0% by
volume of all other chemicals not listed in Table 86A are not covered by this exemption.

* NOTE: Other chemicals not specifically included within the
classes defined above are not approved. Examples of non-approved
chemicals: aromatics (other than those listed or those found in the
crude oil and refinery liquids as listed); aldehydes; amines;
amides; imines; nitriles; halogenated compounds; sulfonated
chemicals; cyanates; organic acids; ethylene oxide (EtO), propylene
oxide, and other oxygenated compounds not listed; organometallic
compounds; pesticides.

(d) The oven, furnace, and/or incinerator shall be equipped
with an afterburner automatically controlled to operate with a
minimum temperature of 1,400degrees Fahrenheit and a gas retention
time of 0.5 second or greater.

(e) Opacity of emissions from the oven, furnace, and/or
incinerator shall not exceed 5.0% averaged over a five-minute
period.

(f) Manufacturer's recommended operating instructions shall be
posted at each oven, furnace, and/or incinerator; and each unit
shall be operated in accordance with these instructions.

(g) Heat shall be provided by the combustion of sweet natural
gas, liquid petroleum gas, or Number 2 fuel oil with no more than
0.5% sulfur by weight; or by electric power.

(h) The emission of any air contaminant shall not exceed 0.5
pounds per hour and 2.0 tons per year.

88. Direct flame incinerators
installed for the purpose of reducing or eliminating
non-halogenated volatile organic compound vapors and/or aerosols
(but not liquids or solids), provided the following conditions are
satisfied:

(a) Before construction begins, the facility shall be
registered with the Texas Natural Resource Conservation Commission
(TNRCC) Office of Air Quality in Austin using Form PI-7.

(b) Each direct flame incinerator shall be automatically
controlled to maintain a minimum temperature of 1,400 degrees
Fahrenheit in the combustion chamber (secondary chamber if dual
chambered) and a gas retention time of 0.5 second or greater.

(c) Continuous temperature monitors to record the temperature
of the combustion chamber (secondary chamber if dual chambered)
shall be installed and maintained. Temperature data shall be
maintained on a rolling two-year retention basis and shall be made
available at the request of personnel from the TNRCC or any local
air pollution control program having jurisdiction.

(d) Manufacturer's recommended operating instructions shall be
posted at each incinerator and each unit shall be operated in
accordance with these instructions.

(e) Opacity of emissions from the incinerator shall not exceed
5.0% averaged over a five-minute period.

(f) There shall be no obstructions to stack flow, such as by
rain caps, unless such devices are designed to automatically open
when the incinerator is in operation. Properly installed and
maintained spark arrestors are not considered obstructions.

(g) Heat for the incinerator shall be provided by the
combustion of sweet natural gas, liquid petroleum gas, or Number 2
fuel oil with no more than 0.5% sulfur by weight or by electric
power.

(i) This standard exemption shall not apply to catalytic
incinerators, or direct flame incinerators installed to control
emissions from new or modified facilities subject to the
requirements of 30 TAC Chapter 116.

89. Ethylene oxide (EO) sterilizing
chambers/operations provided that the following conditions are
satisfied:

(a) All sterilizers must meet the following conditions:

(1) EO shall only be handled by medical professionals or
appropriately trained personnel in medical and industrial use
areas.

(2) Written records shall be maintained for a minimum of two
years and shall be made available to representatives of the Texas
Natural Resource Conservation Commission (TNRCC) upon request.
Records shall include:

(A) Documentation of the date and time of each sterilizer
operation cycle.

(B) The total pounds of EO purchased and used per calendar
year listed as monthly totals.

(C) Leak test results.

(3) Leak tests of each sterilizer system shall be performed at
least every six months. Results of the tests shall be made
available to the TNRCC upon request.

(4) EO shall only be used alone or in combination with carbon
dioxide, nitrogen, chlorofluorocarbon, hydrochlorofluorocarbon
diluent gases, or other mixtures as approved by the Executive
Director.

(5) The sterilizer vent system exhaust stack shall meet the
following conditions:

(A) The stack shall be uncapped and exhaust vertically upward.

(B) The stack height shall be extended to at least 15 feet
above the roof line of the building; and the stack tip shall be
located at least 25 feet from any opening to the building interior,
such as fresh air intake, unsealed windows, or pedestrian traffic
areas. Stacks on multi-level roofs must only extend 15 feet above
the roof upon which the stack is located.

(C) Stack exit velocity shall be at least 50 feet per second.

(b) The following conditions apply only to sterilizers that
use less than 100 pounds of EO per year:

(1) Sterilizer systems which vent entirely to atmosphere shall
not exceed 0.5 pounds of EO used per cycle. Sterilizer systems
which use nonrecirculating, water sealed vacuum systems shall not
exceed two pounds of EO charged per cycle. For facilities with
multiple sterilizers, the usage rate is based on total EO usage at
any given time.

(2) Any combination of sterilizers located on the same or
contiguous property under common ownership shall not exceed a total
EO usage of less than 100 pounds per year.

(c) The following conditions apply only to sterilizers that
use between 100 and 1,000 pounds of EO per year:

(1) Before construction begins, the facility shall be
registered with the TNRCC Office of Air Quality in Austin using
Form PI-7.

(2) The sterilizer chamber exhaust shall vent through an
emission control device that will continuously achieve a minimum EO
removal efficiency of 99%. Thermal incineration shall not be used
to control sterilizer exhaust emissions if chlorofluorocarbons are
used as a diluent. Within 60 days of start-up, the control device
performance must be verified through stack testing or other TNRCC
approved test methods or procedures.

(3) There shall be no discharge of water containing dissolved
EO through a sanitary sewer system.

(4) Any combination of sterilizers located on the same or
contiguous property under common ownership shall be limited to a
total EO usage of 1,000 pounds per year.

(5) Existing facilities which emit 100 or more pounds per year
and can meet the conditions of this exemption, shall have the
control measures in place no later than March 1, 1994.